A fuel cell stack provided in a fuel cell vehicle includes a manifold block assembly which allows gases and coolant to be introduced into the fuel cell before being reacted and to be discharged from the fuel cell after being reacted.
Known manifold block assemblies are manufactured in one aluminum block form including air inlet, air outlet, hydrogen inlet, and hydrogen outlet lines.
However, due to a complicated structure, the manifold block assembly can be manufactured only by sand casting, such that it is difficult to secure a product quality. In addition, the productivity is also low.
Moreover, since the air inlet line is made of aluminum, temperature of an inflow air which is introduced through a humidifier at the time of start-up at a low temperature of −25° C. is decreased by 6° C. or more while passing through the manifold block. This reduction in temperature hinders cold startability of the fuel cell vehicle.